System for starting and operating gaseous electric discharge devices



Sept. 20, 1932 w. A. D. EVANS 1,878,479

SYSTEM FOR STARTING AND OPERATING GASEOUS ELECTRIC DISCHARGE I DEVICES Filed Sept/15. 1929 3 Sheets-Sheet 1 IN VENTOR A TOR EY Sept. 20, 1932. w, A D, EVAN 1,878,479

SYSTEM FOR STARTING AND OPERATING GASEOUS ELECTRIC DISQHARQE' DEVICES Filed Sept. 13. 1-929 3 Sheets-Sheet 2 INVENTOR iiISA TTORNE y Sept. 20, 1932. w, EVANS 1,878,479

SYSTEM FOR STARTING AND OPERATING GASEOUS ELECTRIC DISCHARGE-DEVICES- Filed Sept. 15. 1929 3 Sheets-Sheet 5 IN VENTOR BY 6mm w l HLS'A TTORNE y Patented Sept. 20, 1932.

UNITED STATES PATENT oer-ice WILLIAM A. D. EVANSQOESUMMIT, NEW JERSEY, ASSIGNOR TO GENERAL ELECTRIC VAPOR LAMP COMPANY, OF HOBOKEN,

JERSEY NEW JERSEY, A CORPORATION OF NEW sa's'rnm FOR srenrme AND orm'rme" easnousnmcrmc mscnanen DEVICES Application filed September 1a, 1929. Serial no. 392,354.

The present invention relates to gaseous I discharge devices, and particularly to a method and means for initiating and maintalning a discharge therein.

A particular object of the invention is to provide an improved method of starting a number of discharge devices, either simultaneously or in sequence. A 'furtherobjectof the invention is to provide a simple'discharge starting apparatus which will automatical y start a discharge according to my new method and which will function only while the devices require it. Other objects and advanta es of the invention will appear from the to lowing detailed specification, or from an inspection of the accompanying drawings:

The invention consists in a new and novel method, and in a new and novel combination of parts, as hereinafter set forth and claimed. I have discovered that by afsuitable combination of auxiliary apparatusg the starting of a lamp may be made automatic, this combination further providing means for starting simultaneously or in sequence a number of discharge devices, each ofwhich cooperates in a suitable manner with the starting apparatus to govern theopcration thereof.

- The apparatus of my invention therefore. makes possible. the starting of commercia installations with improved results. For purposes of illustration I have shown several embodiments of my invention in the accompanying drawings, in which sealed therein a Fig. 1 is a schematic diagram ofa preferred form of my invention, designed for In-the drawings, withspecial reference to Fig. 1 each of the. aseous discharge devices 1, which maypfgar-mstance, contain neon or any other suitable gaseous atmosphere, has

cat ode 2 which is adapted to heated by a filamentary heater 3, and.

a pair of separated anodes 4. Each'of the cathodes 2 is connected through an inductance 5 and a common lead 6 to a midpoint of the auto-transformer 7-, said transformer being energized from a suitable source-of alternating current through the leads 8. Each of the filamentary heaters 3 has .one end thereof attached to its associated cathode 2, while the other end of each heater is connected to one terminal of the respective low voltage secondaries 9. The other terminal of each secondary ,9 is connected to the respective cathode 2, so as to complete each of the independentheating circuits. One anode 4 of each discharge device 1 is connected through its respective ballast "resistance 1Q to a common lead 11 which connects with one end of the auto-transformer 7, while the other anode 4 of each discharge device 1 is connectedthrough a similar resistance 10 to a common lead 12 which connects with the other end of saidauto-transfo'rmer 7 These cuits of the discharge devices.

For control of thestarting apparatus a circuits comprise thenormal operating cirmercury switch 15 is associated with each of the .inductances '5, each switch 15 being normally closed, but being moved to open-circuit position magnetically when the core of the associated inductance 5 is magnetized by the passage of a discharge current therethrough. One terminal of each switch 15 is connected to a common lead 16 which in turn connects with the lead 6; The other terminal of each switch 15 is connected through a common lead 17 resistance 18, and the primary 19 of a high frequency oscillator to the lead 11'. A- bimetallic element 20 which is in close proximity to the resistance 18 is adapted to short circuit said resistance,

after the elapse of a predeterminedtime, under the influence of heat generated m the resistance 18 by a current passing there-' through. A secondary coil 21, in inductive -95- terminal connected to an end of said prirelation'to the primary 19, and having one mary, has connected across the terminals thereof a sparkgap 22 and in parallel with said spark gap a condenser 23 and a few turns of the coil 24. l The free end of the coil gin Fig. 2, a thermally responsive device, such as a bimetallic element 27 and a contact 28 is positioned'adjacent to the cathode 2 of each discharge device, these bimetallic elements intercepting sufficient radiant heat therefrom when the cathode 2 is at operating temperature to be deformed into circuit makingposition with the associated contact 28. These contact 'making devices are connected in series between the lead 17 and a point between the resistance 18 and coil 19, so as to short circuit said resistance 18 when all of the cathodes 2 are at operating temperature.

With reference to Fig. 3, the circuit is identical with that of Fig. 1 except. for the connections between the inductances 5 and the common lead 6. The inductance 5 of device I, which is designed to be the first to operate, is connected to the common lead 6 through a heating resistance 29. A bimetallic element 30 which is in thermal relation to said resistance 29 is adapted to close a similar circuit from the inductance of device II through a heating resistance 29.to the common lead 6 after current has passed therethrough for a predetermined time. Similarly a bimetallic element 30', which is actuated by heat from the resistance 29, is adapted to close a circuit from the inductance of device III directly to the common lead 6, unless it is desired to operate more than three devices, after current has passed through said resistance 29 for a-predetermined time interval.

In the operation of the apparatus of Fig. 1, upon application of an alternatingpotential to the leads '8 current immediately flows through each of the circuits formed by a secondary 9,. filamentary heater 3, cathode 2, and the associated leads, the cathodes 2 being heated thereby. At the same time current flows from auto-transformer 7 through lead 6, lead 16, each of the switches 15 in parallel,

" lead 17, resistance 18 and primary coil 19 to lead 11, thence returning to the auto-transformer 7. The resistance 18 so reduces the potential dropacross the oscillator primary 19 that the induced potential in the secondary 21 is insuificient to cause a discharge across the; spark gap 22, so that as long as the resistance 18 is .in circuit no high freuency current is generated. At the same t1me the heat generated in the resistance 18 starts to deform the bimetallic element 20. After a predetermined time interval, which is made to correspond with the time requlred to heat the cathode 2 to a proper electron emittlng condition, the bimetallic element 20 is deformed sufiiciently by the heat transmitted from the resistance 18 to short circuit said res1stance.- As the full operating potential is thus impressed on the oscillator 19 a spark discharge is started across the gap 22, which allows the condenser 23 to discharge through the spark, thus developing a high frequency oscillating condition 'in the spark gap condenser 23 and coil 24. These high frequency oscillations are conducted to the electrodes 26 by the lead 25. A high frequency discharge to the envelopes of the discharge devicesl thereupon occurs which results in the initiation of a discharge in each of said devices. As the discharge starts in each de vice 1 its associated inductance 5 becomes energized and actuates the associated switch 15 to an open circuit position. As the last switch 15 thus opens the oscillator primary the starting of any of the devices 1 the element 20 may cool sufficiently to reinsert the resistance 18, but this automatically reheats the element 20, until it again short circuits the resistance 18, so that the high frequency will be recurrently applied to the devices 1 until a discharge has been started in all of them. In case the discharge is interrupted at any time in any of the devices 1 its associated switch 15 will immediately close, energizing the starting apparatus after the predetermined interval required to heat the element 20 in the same manner as described above in detail in connection with the starting of the discharge in all of the devices l, until a discharge is again started in that device,

whereupon the switch 15 is reopened and the oscillator deenergized.

- In the modification of this circuit shown in Fig. 2 the addition of the bimetallic elements 27 and contacts 28 eliminates the delay substantially the same time. The high he 'quency oscillator is thus energized, and continuously remains so until a discharge is initiated in all of the devices 1, since the short circuit of the resistance 18 is maintained by thecircuit through the elements 27 and contaets 28, rendering ineffective the opening of the circuit by element 20 as it cools. After all the discharge devices are in operation the oscillator is deenergized, as before, by the opening of the last switch 15 as the discharge is initiated in the device 1 associated therewith. An important difference in o eration occurs, however, when a discharge Fails for any reason in any of the devices 1 while the cathode 2 thereof is at operating tempera-- 19 is deenergized. 'In case ofa delay in ciated with the device 1 in which the discharge has failed, thus eliminating the delay which is unavoidable where only the bimetallic element 20 is used. After the interrupted discharge is again initiated the switch 15' will reopen as before to deener ize the high frequency oscillator. In case 0 failure of any of the cathode heaters 521 the circuit through the elements 27 and contacts will, of course, be rendered inoperative, but the remainder of the discharge devices will continue to o erate in the manner previousl described or the circuit of Fig. 1, in whic this additional control circuit was not used. With the modification shown in Fig. 3 the starting of device I is the same as that previously described in connection with the apparatus of Fig. 1. Device II and device III are initially rendered inoperative, however, by the open circuits existing at the thermal elements and 30, respectively. When the discharge is started in device I, however, the thermal element 30 is heated by the passage of current through the resistance 29 until it closes the circuit from the cathode of device II, whereupon a discharge will'be started in said device by the high frequency electrode 26, since this electrode is intermittently energized by the recurrently closing thermal element 20. The passage ofthe discharge current through device II then heats the thermal element 30 by means of the resistance 29', closing the energizing circuit of' device III, a discharge thereupon being started in said device in the same manner as in device II.

While I have described the method and apparatus of my invention in connection with a specific gaseous discharge device, and in connection with single phase alternating currents, it will be understood that either is equally useful with other types of discharge devices which require auxiliary starting. means, and that by obvious modificat ons either the method or the apparatus may also be employed on direct current and polyphase alternating current devices. It is furthermore to be understood that if desired the steps of the method may be performed manually and that various other substitutions and changes may be made either in the method or in the apparatus illustrated and described, without departing from the spirit of my invention.

' I claim:

1. In-combination, a gaseous discharge de v vice, a discharge maintaining circuit therefor, means to produce a high frequency discharge in proximity to said device to initiate a discharge therein, and means to energize for, means to produce a high frequency discharge in proximity to said device to initiate a discharge therein, and means to energize said last named means at a predetermined time interval after said discharge maintaining circuit is connected to a source of energy. and to deenergize the same when a discharge is initiated in said discharge device.

4. In combination, a gaseous discharge device having a cathode adapted to emit electrons when heated, a discharge maintainingcircuit therefor, means to heat said cathode, means to produce a high fr quency discharge in proximity to said device to initiate adischarge therein, and means to render said last named means operative after said cathode reaches operating temperature.

1 5. In combination, a gaseous discharge device having a cathode adapted to emit electrons when heated, a discharge maintaining circuit therefor, means to heat said cathode, means to produce a high frequency discharge in proximity to said device to initiate a discharge therein, means to deenergize said discharge producing means when said cathode is not at operating temperature, and means to deenergize said discharge producing means when a discharge is maintained in said gaseous discharge device.

6. In combination, a plurality gaseous discharge devices, a discharge maintaining circuit therefor, means to produce a high frequency discharge in proximity to each of said devices to initiate a discharge therein and means to energize said last named means at a predetermined time interval after said discharge'maintaining circuit is connected to a source of energy.

' 7. In combination, a plurality of'gaseous discharge devices, discharge maintaining circuits therefor, means to produce a high frequency discharge in proximity to each of said devices to initiate a discharge therein, and means responsive to energy flow through'said devices to deenergize said discharge producing means when a discharge is maintained in all said gaseous discharge devices.

8. In combination, a plurality of gaseous discharge devices, a discharge maintaining circuit therefor, means to produce a high frequency discharge in'proximity to each of and means to energize said last named means at a predetermined time interval after said discharge maintaining circuit is connected to a-source of energ and to deenergize the same when a discharge is maintained in all of said devices. I

9. In combination, a plurality of gaseous discharge devices having cathodes adapted to emit electrons when maintaining circuit therefor, means to heat said. cathodes, means to produce a high fre- -"quency discharge in proximity to each of said devices to initiate a discharge therein,

and means to render said last named-means operative after said cathodes reach operating temperature. v

10;. -In combination, a plurality of gaseous discharge devices having cathodes adapted to emit electrons when heated, a discharge maintaining circuit therefor, means to heat said cathodes, means to produce a high frequency discharge in proximity to each of said devices to initiate a discharge therein, means to energize said discharge producing means when a discharge is not maintained in any of said discharge devices, and means to render said discharge producing means inoperative for a predetermined time to allow said cathodes to attain operating temperature.

11. In combination, a plurality of gaseous discharge-devices having cathodes adapted to emit electrons when heated, discharge maintaining circuits therefor, means to heat said cathodes, means to produce a high frequency discharge in proximity to each of said devices to initiate a discharge therein, means to energize said last named means Whenever a discharge is-not maintained in all said dlscharge devices, means to render said discharge producing means inoperative for the interval required to heat saidcathodes to operating temperature after actuation of said energizing means, and means responsive to the thermal condition of said cathodes to render said last named means ineffective if said cathodes are at operating temperature.

12. In combination, a plurality of gaseous discharge devices having cathodes adapted to emit electrons When heated, discharge maintaining circuits therefor, means to heat said cathodes, means to produce a high frequency discharge in, proximity to each of said devices to initiate a discharge therein and means to prevent the initiation of a disated, a dischargetermined time interval after the initiation of a discharge in another of said devices.

14. In combination, a plurality of gaseous discharge devices, discharge maintaining circuits therefor, means to produce a high fre- 1 quency discharge in proximity to each of said devices to initiate andischarge therein, means to render said last named means inoperative untila predetermined time interval after said discharge maintaining circuits are connected to a source of energy, and means to delay the initiationof a'discharge in one of said devices until a predetermined time interval after the initiation of a discharge in another of said devices.

- 15. In combination, a plurality of gaseous discharge devices, discharge maintaining circuits therefor, and means to initiate a discharge in said devices comprising a single generator of high frequency current, an electrical conductor therefrom terminating at a point adjacent to each discharge device,

means to energize said generator when said devices are in a condltion to support a normal discharge current, and-means to deenergize said generator after a discharge has been initiated in each of said devices.

Signed at Hoboken in the county of Hudson and Stateof New Jersey this 12th day of September A. D. 1929.

' WILLIAM A. D. EVANS. 

